Repair and Diagnosis of Problems with Your Imperial's Battery


Imperial Home Page -> Repair -> Electrical System ->Battery  

Tip-What to do if you have no juice...

Put the multimeter across the battery terminals. 12 volts?? No, then charge the battery and re-test. 12 volts? No, then junk the battery and get a new one.

If you get 12 volts at the battery terminals then leave the + lead on the + battery terminal and move the - (negative) lead to the engine block - find a good clean metal surface on the engine and see if there is a 12 volt reading. No, then there is a bad ground cable from the battery to the engine.

If yes, then put the - lead back on the battery and move the + lead down to the next available measurement point, normally the fat lug on the starter motor solenoid. 12 volts?? No, then you have a bad battery cable or terminal.

If yes, then move the + lead to the BAT terminal on the alternator. 12 volts? If not, then you have a burned out fusible link or broken wire .

Yes, then move the + lead to the + terminal of the main fuse block in the car. 12 volts?? If not, then you have a burned fusible or broken wire going to the fuse block.

The basic idea here is to start at the source of energy, the battery, and then move further and further away from the battery (assuming it is good) until you no longer get a 12 volt reading. Then look for burned wires, burned out fusible links and broken connectors. It's not rocket science but it does require an orderly process to isolate the problem.

Tip from Brad:

I posted to the list week before last about the battery in my '66 going dead all of a sudden-like. Last night I may have found the cause. The fan for my HVAC system stays on unless the "OFF" button is pushed in, even with the key off! I remember having pressed the "FRESH COOL" button in, to test the system, while driving it last time. I drove it yesterday and stopped for some dinner. I had the fresh cool button in again. When I stopped the engine and pulled out the key, the fan was purring away. I pushed the off button and off it went. This can't be normal operation. I guess I'm going to have to get into the dash wiring sooner than I thought.

Tip from Bob:

I, too, have heard the "old wives tale" of a battery discharging if left on a cement floor. It ain't so, folks. Within the last several months, I read in one of the 5 automotive magazines I subscribe to, a test that was performed in the Midwest. There is nothing in cement or concrete that will cause a battery to discharge. A more reasonable explanation is cold. There was even a table of temperatures and electrolyte readings that would result in a battery freezing. An old battery where much of the sulfide particles have fallen off the plates onto the bottom of the battery case will go dead but this is because it will short out one or more plates. If a battery is kept charged, either with a trickle charger or other means, it will not discharge whether it is places on concrete, wood or rubber. I use a standard batter charger (that does not have the feedback feature) plugged into an ordinary lamp timer with the on and off tabs set together (about 5-8 minutes of charge) and the charger set on 2 amps. This is enough to keep it fully charged but not too much to overcharge.

Tip from Gregg:

If your car will not start and you know the problem is with the battery, make sure and check the ground.  To repair my charging problem, I took apart the marine style battery cable (positive) and replaced the old 12 gage ground with a new piece and replaced the skinny 16 gage wire I had crimped onto the new negative cable with the 12 gage also. When it STILL didn't start, I relocated the ground for the negative cable from the fender to the cowl-to-fender bracing. Then it cranked well.

Question from Loyal:

My '66 Imperial Crown Coupe has been at the body shop for several weeks now...(don't ask). Before I sent her off I had purchased & installed a new battery...not a cheap one, but a good one. I have just heard from the body shop & they say the battery is completely dead & can't be charged...(which is what happened to the one prior to this). Now here is my question, Is this an altenator problem or the fact that they probably havn't started it much & let it drain? Is there maybe a short that is draining it off? Will Advance Auto take back the battery after 2 months?


From Bill:

It is not at all uncommon for a "new" battery to be bad. Not sure what the body shop means by "can't be charged", I assume it's "won't hold a charge"?? If it won't hold a charge, take it back to Advance and have it tested. Their "better" and "best" batteries usually carry a warranty that specifies free replacement for a limited time, after that, it will be pro-rated depending on the length of warranty period. It just depends on what battery you bought.

From Paul:

New batteries often need to be used for a while before they sit too much. I bought a new battery for one of my cars, and then immediately afterward had a fuel problem which lead to me cranking the engine too long, thus draining the battery.

I was able to charge it, and get the car to run after fixing the fuel problem, only to leave the car at the local glass shop the next day for a new windshield and have a problem all over again.

While they were changing the windshield, they left all of the doors open, all day with the interior lights on. Remember, this is just after I drained the battery trying to crank it with no gas. This time the battery was dead, so they put a charger on it for an hour which did nothing. We jumped the car with their van, so I got home.

Two weeks later I bought another new battery. I don't think I would blame the battery in this case, just a lot of bad luck and some dummies at the glass shop. By the way, the dummies decided that they had to smash the windshield to remove it from the car, so even after six months I am still finding glass shards in the seats and carpet.

From William:

I suspect that your existing "new" battery can be brought back to life with an overnight slow charge or a charge with a self-regulating charger. Most body shops and other mechanic shops have chargers that are time-limited and usually of the "fast charge" orientation. It could well be that their charger was too much or they didn't try another approach, but just wanted it to happen pretty quickly as it might for a more seasoned battery.

Even with a regulated charging rate charger, it might read "zero" for a while after its first hooked up, but then after a while it'll start taking a charge and the charger will be putting out about 3/4 of its rated charge amount. With time, the charge rate will diminish until the needle is bouncing off of the "fully charged" mark. It might take several hours and the slower it happens, the better.

Of course, you could get your purchase documentation and see if the seller will replace it under warranty, BUT many of those vendors will want to load check the battery first and that takes an overnight charge in many cases. In other words, if it's just a low state of charge, it's a different situation than if it just will not hold a charge or has low capacity due to a weak cell.

Also, even new batteries are not at even 90% of total charge capacity "as delivered". Therefore, if you sent the vehicle to the shop with a 70% charge, for example, and it sat and was run down (some how or another), then it might be "dead" much sooner than if it's been fully charged (meaning the charger would not charge it any further).

I highly suspect that if you take the battery, clean the terminals and cable ends (probably already done), and put it on a good self-regulating charger overnight, and then keep it charged for a while afterward, it'll probably be very useable. That time frame might not suit the body shop people so that's another something to consider too, just as buying another less expensive battery to put in the car while your other more expensive battery is being recharged.

From Anthony:

Did the body -shop take the "power-connection" off the battery---when the doors--trunk are left open for hours--that will drain the battery dead!

From Quint:

I had a similar experience with my 1953 Imperial. In my case the clock was used up all the juice in the 6 volt battery while the car sat in the garage. I disconnected the clock and all is well. In my case however, the battery took a charge with no problem.

From Jan:

For what it is worth one of the best things I have done to my 1955 is install the battery disconnect switch. Now, anytime I stop I merely disconnect, and when I return the car starts.

Question from Henry:

Using a correct period battery for a '56 Imperial. Having poor luck with them as first two were duds and the third is now poorly performing. No help from manufacturer on shipping damage, etc., etc. So considering an Optima battery inside a correct case. I have heard that is done or is possible. Any experience with that out there? Where does one get an empty case? Would I have to make one up myself emptying out one of the bad ones? Sounds messy to me.

Maybe there is advice and/or experience to relate???


From Paul:

One of the other clubs that I belong to for another make of car (that has 12 cylinders) features a member who makes batteries up just as you describe for those cars.

If you contact me off list, I will provide you with contact information so that you can talk with him about the process. I believe that he actually puts the batteries together prior to sale, but he may be able to tell you how it is done.

I am not that particular myself.

From Chris:

I bought an Optima battery for my '62. It's the best (and most expensive) battery I have ever owned. However it looked very ackward under the hood after all of the trouble I took painting things and placing decals on things for authenticity.

So I too looked around for a cover, and I found one through Eckler Corvette. At the time, they were the only ones to provide a vintage looking cover designed to fit over the Optima. To make the long story short, it beats nothing, but it's not the best in fit or finish. It's a cheesy vacuum formed ABS molding with a separate piece that has only three sides to it to cover the sides of the battery. Not the best solution since the battery in the Imperial is pretty exposed and visible on all sides. On a Vette, it probably looks good since the battery lies out of sight at the bottom of the engine compartment. So I wound up getting some black plastic panels from the local hobby shop and made my own "sides" of the battery. The other goof is that the little molded screw on lids have Delco stamped on them. I'm fairly satisfied with it since it still gives the engine compartment a vintage look. I bought this piece about a year ago, and I have noticed that now someone else offers a s!
imilar cover for vintage Fords.

At a local car show a fellow I know took things a step further. He actually took an old tar top battery and gutted it. Then he stuck the Optima inside it. It was a fair butcher job, but after all the trouble he probably went through, the look wasn't any more convincing. You see, the posts on the Optima are located differently from a traditional battery, so that's where the problem lies with any solution you choose.

From Eric:

I'm almost positive that I saw an ad in Old Cars Weekly where one of the firms that markets "new" versions of OEM batteries also offers Optima "cores" that have been placed into NORS shells of older style batteries.

Question from Dan:

Should I be charging the battery while it is hooked up to the car, or should I disconnect it? The charger is one that can be left on indefinitely and will maintain the correct level.


From John:

If your charger is designed to maintain a floating charge, there's no reason no t to leave it hooked up.

Or, simply disconnect your battery, charge it, remove the charger and give it a refresher charge in 4 to 6 weeks.

From Dick:

It won't hurt anything to charge the battery with it hooked up to the car, unless you have worries about rodents or other damage to wiring which could cause a fire. In our area, I never leave a battery hooked up in my storage buildings - I just leave one terminal barely snug on each car, and lift off one terminal whenever I am leaving the car for more than a day or two.

From Ray:

I really don't think it would hurt anything. I have done it several times and has not hurt anything. I talked to a battery guy at East Penn Batteries about doing that once and said hooking up a battery left on a car without a computer could not hurt anything as long as the type of charger that cuts off by its self and does not over charge.

Question from Rob:

I am having a problem with my battery.  The positive cable won't tighten and I haven't gotten around to replacing it, because it's the original and has different wires running off it. When I attach it the interior lights, etc. come on, but sometimes when I go to start it- "click" and everything goes off. You may have to wiggle it a few times before it will crank. Why does it do this? I would have thought it would be attached or not. I don't understand why cranking it will kill all power.


From Demetrios:

The spark caused by the very high current may be creating an insulating layer. Tighten the electrode. If the electrode is corroded and cannot tighten any further, the fastest solution to eliminate the problem is to install a piece of aluminum foil between the battery terminal and the lead electrode. This will act as a conducting shim and increase the pressure between the terminal and electrode, as if you had tightened the nut.

From Russell:

Because when the loose connection is overloaded by starter it arcs and looses connectivity. You should always tighten the battery cables to ensure full battery power to all accessories including the starter.

Question from Bill:

 My battery will not hold a charge overnight.  Is there a drain somewhere or something else I should be looking for?

Reply from Norm:

If you have tried all other avenues without success, don't forget to look at the battery itself.  I would take the battery back to where you purchased it and return it.  The battery may be defective and not charging properly.

Question from David:

Does anyone have any advice to offer on finding an electrical short in a car? My car has a short of some kind that kills the battery over a period of a few days when the car sits in the garage. I don't recall ever having tackled such a problem in the past. Where does one began, the fuse box perhaps?? I know there must be a general set of methods/steps for finding electrical problems. 

Reply from Dick:

If your problem is draining your battery in a few days, the current will be in the 1 AMP range, probably. This could be something like the under-hood, trunk or glove box light staying on, or a power antenna that does not shut off when it is all the way down, so you might want to check those items first, before pursuing the next step. You can check the antenna motor by seeing if it is warm when the car has been parked for a while. Another source of this type of drain is a horn relay stuck on, but if this were the case you would be tipped off because your horn wouldn't work (having been disconnected by the last owner.) 

If this doesn't yield results, you need to go to step #2. 

You need to obtain a VOM (Volt-Ohm Meter) with a DC amperes scale that goes at least to 3 Amps, 10AMPs would be better. Connect this meter in series with the cable that goes to the + terminal of the battery. Observe that there is some current flowing.

 Next, remove the fuses from their clips one at a time, checking the current drain after each fuse is pulled. When you reach the fuse which powers the offending circuit, the current drain will disappear. Now, reinstall all the previously pulled fuses and make sure there is still no drain. Assuming there is no problem as long as the last fuse is still out, operate all the items on the car to see what is without power, or read in your manual to see what items are powered by that last fuse. One of those items is the offending part, or the wire leading to it is contacting something it shouldn't. Since this is such a low drain (if it takes days to drain the battery), the problem is very likely to be something left on that shouldn't be, rather than a short or miswire. 

If none of these things leads to a bad fuse (that is, all the fuses are out and the current drain is still showing), try disconnecting the large wire from the alternator. If this makes the drain stop, you have a bad diode in the alternator. 

If you want to avoid the expense of getting a VOM, you could try doing this same test by disconnecting the + terminal of the battery, and then tapping it in the hope of seeing a small spark when you make and break the connection. If you can see the spark, you can use this test as an indicator of current drain. Whether or not you can see it depends on many factors, but the meter method is foolproof.

(Check out the tool Kerry invented to replace a VOM.)

Question from Jerry (1955):

I need to replace my 6-volt battery. I would be grateful for any suggestions. Does Optima make a 6-volt? Where do you purchase this brand?


From Jan:

I bought an Optima for my '55 (6v), it didn't seem to be much different than others. When it died, probably more than a year ago, I installed the 6/12 system from Antique battery. I am completely satisfied with it. The car starts like 12 volt and the generator seems happily able to keep it charged.

From Roger:

My '55 has an Optima 6 volt battery that came with the car. They are available on the Web for about $103. Sears carries 12 volt Optima in their store, and they may be able to order a 6 volt version.

From Chris:

Optima does make a 6 volt battery. I don't know what the part number is. I saw some at my local Interstate Battery store. You may want to try there if there is such a store in your area.

Question from Bill (1955):

My battery is not getting a charge. With engine running and when I disconnect the wires at the battery the engine stops. It might be time for a generator rebuild.

Does the generator and power steering pump need to be removed as one unit, or is it possible to unbolt the power steering pump THEN remove only the generator. I wanted to try and avoid disconnecting the power steering lines and a mess from the fluid reservoir.


From Rodger:

Two bolts hold the power steering unit to the rear of the generator. Remove them and then the 37 lb generator. Make sure that you place sumthin on the fender of your Imperial so that your belt buckle does not get to the paint.

From Paul:

The power steering pump un-bolts from the back of the generator. There is a rubber coupler that goes between them which you may find to be bad. Replace it if you can. The one in your car may be reusable, but its probably fragile so be careful.

Question from Don (1955):

Has anyone found a good 6 volt battery that has lots of cranking power for my 1955 hemi Imperial?


From Roger:

I bought the biggest case, most number of plates, largest cold cranking amps, and best warranty offered at Carquest. That was 2 years ago. The car starts in -15 deg weather and has never failed me. The secret is to double the cold crank amps compared to cubic inches. A 331 Cubic inch needs 600 cold crank amps to work correctly. The biggest I could find was a 550. I was worried at first, but it has never failed. Most of the battery companies have discontinued the big 6 volts except truck applications. If all else fails go to a truck repair center.

From Dick:

Optima Batteries. Accept no substitute.

Also, make sure your cables are 2-ought cables (NOT #2!), and have clean bright connections on both ends of both cables, and that your ground from the starter to the block is also clean bright bare metal (starter mounting bolts).

From Rodger:

For my '47 I got a big sized golf cart battery. Give them the size of your battery tray and then the height. The size is related to cranking, and cranking and cranking power.

From B.A.:

Being the proud owner of a 1947 New Yorker Brougham and a 1948 DeSoto Custom Sedan, I know the problems of needing a quality 6 volt Battery. Try your local Mack truck dealer...tell them what you need and I'm quite sure they can help. I've been fortunate to find an 1100 CCA 6-volt that starts either of the above mentioned cars quickly and perfectly. It fits the Factory tray for both cars but JUST fits. The last one I bought was in 2001 and the price was $69.00. Just keep it charged. I own an Optima 12 volt and its grand...never owned a 6 volt.

From Jan:

The guy that rebuilt my 1955 radio told me that if I had ever used an 8v battery my radio was "toast" !! I also tried an Optima and it was no better than anything else. I now have the 6-12 system and the car starts swiftly everytime!!

Question from Roddy (1955):

 I bought my 1955 Newport one year ago tomorrow, September 30th.  I elected to retain the original 6-volt electrical system. My problem is that when I drive the Imperial the scant  fifteen miles from the garage to my house, the car refuses to start until it cools down. Even when it starts "well" the engine seems to delay an inordinate amount of time until it decides to kick into action. I drove the car for a few minutes a month ago and then it was towed back for more work in an attempt to solve the restarting problem. My mechanic has added power to the starter somehow, the alternator has been rebuilt, the battery is the most powerful available model, the wiring, of course, is all new.  Needless to say, I am getting frustrated.  

Reply from Dick:

You need to find out what is wrong. Probably, a simple check with a voltmeter will tell you that your starter is seeing less than 4 volts when it is trying to crank! Buy a cheap meter from Radio Shack and see for yourself!

Possible causes are numerous, but in order of likelihood they are: 

1. Wrong size battery cables (gauge should be #00 or larger) and these will have to be made up for you by a battery cable or welding supply house. Do not be persuaded to put smaller cables on it. Use only soldered and crimped cable ends, never the clamp on type. Do not use a disconnect switch on a 6 volt car! The copper in the cable must be 3/8 in diameter or more for good conductivity. 

2. Cables connected in the wrong place, or with less than perfectly clean and bright hardware. The ground (positive) cable should go directly to the engine block, and the starter and the cable must be mounted to the engine block with clean and bright surfaces (NO PAINT!!) on both parts and on the mounting hardware. 

3. Inadequate battery. The battery should have at least 900 CCA rating, more is better. If you cannot find one, try Interstate batteries. If they can't supply one, get an Optima battery. They're expensive, but they will spin your hemi for you! 

4. Starter problems, usually armature dragging on the pole pieces when it is hot. While this is relatively rare, this sounds like a good candidate for your particular problem. Have the starter checked out by someone who deals with heavy equipment starters, not your local auto parts place. Look in the yellow pages and try to find someone with gray hair who has been doing it a while. Tell him about the temperature dependence. 

5. Engine problems. Hate to tell you this, but if the crank saddles were not align bored when the engine was rebuilt, you may never solve the problem. Also, make sure the slow cranking is also present when you pull the coil wire out of the distributor cap and ground it - we're checking here for timing so advanced that it is making your engine kick back against the starter when hot. 

I urge you to find and fix the problem. I am vehemently opposed to 8 volt batteries or 6/12 volt batteries, as they put much more strain on all the other components in the car, and are definitely not needed when everything is as it was when the car was new. The fact that you have spent piles of money on the car does not prove that all of that was done right, or by someone who understands electrical current flow needs. The starter on your car is pulling upwards of 400 amperes - it needs perfection in its power supply hardware! I personally drive 4 different 6 volt cars on a regular basis, all of whom have very heavy and hard to crank engines. They all start immediately, in any circumstance, just like they did when new.  

Question from Hubert (1955):

I recently bought a 1955 Imperial at an auction.  The battery was out of order. I put in a new 6-volts battery, and leave the car for a few hours. 6 to 8 hours later, the new battery was flat and very hot!  What is happening?  Does my car have positive earth?


From Boyd:

The '55 has a positive earth indeed. But, if the battery got hot, recharge the battery very slow and check the acid level. In my opinion, you also have a shortcut somewhere. If you connect the battery again, check it, connect the earth and then push the positive connection cable slightly against the battery. You might not have sparks come off. Check after 5 minutes if the battery remains cold. Check it a few times, just to be sure. 


You should quickly change the positive lead on your car!!

From Dick:

Yes, it is probable that the car is wired for positive ground.  The owner's manual should tell you for sure. Originally, most cars with 6 volts, other than GM cars, were positive ground. HOWEVER, your problem is not because of this. It sounds to me that your regulator cutout contacts have stuck together, probably the generator was also very hot. You need to get the battery recharged, then polarize the generator correctly by momentarily connecting the battery hot lead (- terminal, in this case) to the "A" terminal on either the regulator or the generator. Then, the regulator and/or generator may have been damaged by the stuck contact. If this is so, you will have to replace one or both. Check the ammeter for discharge after you turn off the engine, or if there is only an idiot light, disconnect and tap the negative cable at the battery, to see if there is any current flowing. There should be no spark. If there is current draining, there will be a spark, and there is a problem, probably with the regulator, and you must be sure to disconnect one terminal from the battery every time you shut the engine off, or risk a fire or more damage, continue with this action until you get the problem fixed.

From Greg:

You guessed it, all Chrysler products thru 55 has positive earth, ground.

Follow-up from Jim:

1955 Windsor (C-67), New Yorker (C68), Imperial (C-69) had 6V positive ground systems. The 1955 Crown Imperial (C-70) had a 12 V negative ground system.

Question from Ken (1959):

I have recently run into some trouble with the battery discharging. After being underway I returned and went to the garage to start my car and found the battery dead. I put in a new battery and went for a drive only to find I had no brakelights. The next morning the new battery was discharged. I had charged the previous battery and got the car started. I checked the generator and voltage regulator. I find the battery is being charged, but when I shut off the car the ampmeter is showing a current drain. I have been trying to troubleshoot this by running through all the manual information posted on the OIC site and with postings, and suspect the brake switch is bad, so I am asking the experts out there, am I on the right trail or should I hunt elsewhere?


From John:

I had the same problem on my '56, and found out that the voltage regulator was sticking. A good tap on the shell will unstick it, but the problem may recur. It's an easy task to remove the shell and clean the contact points. I havn't had the problem since.

From Steve:

You can pull the wires off the brake light switch which is on the bottom of the master cylinder and see if the drain is gone. I would suspect that if this were your culprit the brake lights would be on though.

Window switches and power seat switch have been known to stick and cause this problem as well. Voltage regulators can do this too as someone else has already pointed out. If you don't have one get yourself a cheap voltage meter from radio shack. It will come in handy many times!

From Dick:

Yes, you're on the right track. The fact that you can see the drain on the ammeter means that there is a significant amount of current being drawn, so when you park the car, you should lift off one battery cable to stop abusing the battery until you track down the problem. If it is the brake lights, then you should certainly be able to see the bulbs lit. If you can't find it that easily, you'll have to start removing fuses from the fuse holders until you see the current drop off - then you know the last fuse you pulled is for the circuit with the problem. Without putting that fuse back in, try to operate everything electrical in the car. Whatever doesn't work anymore, is on the circuit that is causing the problem. Just investigate those items - one of those is the culprit.

If you can pull all the fuses and still see the current drain, try disconnecting the voltage regulator wires - perhaps one of the internal relays has stuck in the on position. Another sign for this would be the generator getting very hot!

This sort of thing can cause a fire, so be sure to disconnect the battery every time you leave the car, else you risk losing the car.

Question from Bill (1959):

The last few times I went to start my '59 Imperial it didn't have enough juice to crank it over, so I had to jump start it with my other car. Today it was completely dead, and I had to leave the jumper cables on about ten minutes till it finally got enough juice to start the engine. I then took it over to Sears and had the battery tested, which was fine, and he tightened up the belt on my unmentionable thingamajig. He felt I may have a problem with the unmentionable part, so I took it over to my regular mechanic, who found the whole charging system to be working just fine. After turning the car off while still hooked up to the tester you could see an intermittent 20 amp surge, which he thought was my problem. I told him I suspected the rear passenger side window, since at times I could hear a clicking sound from there, and see the voltmeter jump. We then removed the door panel, which takes about three seconds in my car since it is practical ly falling off. The master window switch was very hot on the prongs that went to the rear window, and what we discovered, is since I do not have the bezel in place around the window switches, they had sunken back into the door, and the rear switch being in the first position was slightly wedged under the door panel. Once the panel was off there was no problem. Who would have thought such a dumb little thing could cause such problems!

Reply from Dick:

You are very lucky you didn't have a fire! Those door panels are very flammable.

Any time you see an unexplained twitch on the ammeter (it isn't a "voltmeter", it is an ammeter - it reads the amperes flowing into something in the car), you should IMMEDIATELY disconnect the battery before you lose the whole darn car, GM alternator and all!

Question from Joe (1961):

Does anyone on the list know the correct size battery for this car? I don't mean the physical dimensions, I am asking about cranking amps, etc. I need to replace the battery and don't know what size to buy.

Reply from Chris:

On my '62, I broke the piggy bank and bought an Optima battery. You just can't go wrong with it. You don't have to trickle charge it if you don't drive the car all the time, and it charges up fast too. Now, an Optima looks way out of place in the vintage surroundings of our engine compartments. So I ordered an Optima tar top cover that Eckler Corvette sells. With some slight modifications, you can have the battery look like it belongs there. Kenyon brought up a good point on the battery disconnect switch. It's good practice to keep a battery disconnected from the car as it sits in order to minimize the galvanic effect which aids in the corrosion of body parts.

Question from John (1961):

I want to change my battery cables on my '61. They look like the original ones and are in bad shape . The negative has some exposed wire. What should I use to replace them with? Are there any pitfalls I should know about?


From John:


If you want to stay with an original style, one of the companies that sells the repro style batteries also sells original style cables. I got a pair for one of my 60's & they are just like the originals & not all that expensive. I believe the name of the company is "The Antique Auto Battery Co." I've also bought 2 batteries from them & they provide very good service. Delivery in less then a week.


From Steve:


Get the best cables from NAPA. They have the cables and even have the original sizes available for your car. You want to buy the heaviest gauge cable that you can.

Question from Tony (1961):

I am completely mystified. My '61 won't charge the battery. So far I have established that the alternator (almost new 60 amp) and the regulator work fine All connections are good, and there is 12 V going to the ignition side of the regulator and about 7.5 V leaving the field side with the ignition switched on but without the engine running. The battery is almost new and the ammeter seems to be okay and shows a discharge when the lights are turned on but there is no charge when I run the engine. I am no auto electrician and I have run out of ideas. Has anyone been there and done that? 

Reply from John:

I would try another battery to eliminate that as a possibility, if not that possible bad battery cable. Sometimes these look ok, but under the covering will be loaded with corrosion. I had this on a 63 & couldn't figure why it would barely crank, even with a jump. New cables solved the problem.

Question from Allison (1963):

I noticed that I am continuously loosing water in my battery.  What is the problem?

Reply from Dick:

This is a symptom of chronic overcharging.

Follow-up from Allison:

I checked my battery reservoirs last night and found out that each side was low about 10 ounces of water.  The last time I filled them was probably about 5 months ago. While this doesn't seem extreme, its it above average?  My ammeter gauge always reads a bit to the charge side, never dead center.

Reply from Dick:

That amount of water consumption seems a little high - let me try a step by step process here: 

1. When your car is shut off and everything is turned off, do you notice where the ammeter parks? If it seems to settle to the right of center, try tapping the glass gently, to see if it is just a little sticky. If it comes back to center under those conditions, but reads to the right all the time when the engine is running, even after you try tapping it, it is indeed possible the alternator is still charging too high. 

2. If that is the case, I think your best bet it is to check out the charging system. You can do this yourself if you have a VOM ( and if you are going to maintain an old car I strongly recommend you get one, around $50 at any Radio Shack store), but if you don't have the time or inclination, take it to a good electrical shop and tell them what you suspect. As an aside, in Alison's case, in 1979 there used to be, and possibly still is, a very good shop in Lomita called AVIS ( that's right, same as the car rental outfit, but no relation), as I recall, they were on Lomita Boulevard between Crenshaw and Eshelmann, possibly a block or so east of there, on the south side of the street. 

3. To check this out yourself, begin by carefully measuring the battery voltage with the car engine and all current drains turned off, and measure this right at the battery posts, not even on the connectors, but right on the lead posts of the battery itself. This voltage should be somewhere around 12.8 volts with a healthy battery that has been unused for an hour or so, possibly higher if you have just turned off the engine, but not over 13 volts. Lower is not a problem, in this context. ( If your meter does not have automatic polarity reversal, you will need to put the black lead on the negative or "ground" post, and the red lead on the positive post.) 

4. Now, start the engine, leave it idling and all accessories and lights off; then check the voltage the same way. The battery should now show about 13. 6 volts, any higher indicates it may be being overcharged. Again, lower is not a problem for this scenario. 

5. Next, move your meter to the alternator, and check the voltage on the large wire from the big terminal (there is only one), grounding your meter (black lead) to the case of the alternator. Here, you should read around 14 to 14.6 volts, any higher means your voltage regulator may be calling for too much charging current. All of these readings are appropriate for temperatures in the low 70's. Cooler temps mean higher voltage, and higher temps mean higher voltage, for more information about these variations, see your FSM in the regulator section. 

6. Next turn on your high beams, your radio and your heater (not the AC since that will affect the RPM), and check the voltage at the alternator again, with the engine revved up a little (put it on the fast idle cam, if you can get to it, else have someone else hold it at fast idle) and see what the voltage is. Under these conditions, you should see around 15 to 15.5 volts, any more indicates overcharging. 

If you conclude that your regulator is calling for too much charge, I'd still like to have a pro look at the car, often the cause of this is poor grounding at the regulator mounting surface, but it could be a problem in the alternator itself. That is why these problems are often "solved" by a lazy or mendacious mechanic by changing everything involved, costing you lots of money and making lots of profit, when maybe all that was really needed was a little sandpaper on a mounting flange. 

You could try cleaning the mounting area up yourself to see if this makes any difference to the voltage readings (or the ammeter readings, for that matter).

Question from Patrick (1964):

Seems my charging system is out of commission. My battery is way too low for any kind of starting however the lights seem to still work as well as the power windows, just a bit slower and dimmer. I replaced my alternator with another I have, same with the voltage regulator. All the related wires are solid and verified that they are OK.

I'm lost at this point, I put the other three batteries in other cars that I used on the Crown Coupe during the replacement process and they are holding a charge just fine, just not in my Imperial. Anyone have any ideas for me?


From Mike:

Maybe you have a drain on the battery. There could be something that is causing the battery to run down prematurely. Make sure all dome, trunk, etc lights extinguish, same with brake lights. Then check for possible shorts to ground. Remove the battery cables and put an ohm meter across them, making sure the key is off and all accessories are turned off. If it reads anything other than infinity (or a really really high number) then you have a (partial) short somewhere. If you have a current meter, you can just clamp it onto one of the battery cables with the battery still connected and see if current is being drawn at "rest".

From Chris:

Sounds like the voltage regulator is definitely out of comission. There are two relay type contacts in these regulators, and chances are one or both is sticking. Your best bet is to replace the thing with a solid state equivalent.

From Robin:

I just wonder if you have put a multimeter switched to dc volts across the posts of your battery while the car was running? It will tell you immediately if the alternator is charging or not. Should read between 14 and 14.5 volts DC while running if your battery is low.

From Steve:

Do you have a meter? If not go to Radio Shack and get one. You will need one on the future to track down electrical problems.

With the car running check the voltage on the battery. At a bumped up idle you should have between 13.5 and 14.5 (rough numbers) volts across the battery. If you have this voltage then the battery is charging. Anything below 12.6 is not going to charge the battery.

Another possibility is that something on the car is running the battery down. You can also use your (new?) meter to check for drains on the battery.

Question from Bill (1964):

Today I took my '64 Crown Coupe on a 120 or so mile freeway trip. On the return trip I noticed a rotten egg smell while driving, I was sure it wasn't my car and pay much attention to it. 10 or so mile later after getting home I opened the hood just to check if everything was OK. I found the battery smoking from the filler hole area (with the covers still on) and that smell again. I could hear it boiling inside as well, now some 5 hours later its still warm to the touch and its 35 or so degrees outside. Any ideas on what is going on?

I have just recently bypassed the ammeter in my wiring under the dash, the wiring burnt some months back.


From Roy:

Take the cover off of the regulator and you will probably find the points welded together and a wire melted in half. It sounds like your alternator was working all out.

From Ken:

Your voltage regulator is stuck in charge position, replace regulator. Rewire gage, maybe in-line fuse, this problem is common.

From Ed:

Could be a stuck voltage reg. but my guess is the diodes in the alternator need to be replaced. I've had that problem before and that was the prognosis.

From Dan:

That happened to me a few years ago and I found that the voltage reg. was not grounded good. I sanded the mounting spot and the base of the reg. That fixed it.

Question from Bill (1964):

When our '64 Imperial "was" running then died (rusty fuel tank), while trying to restart it the battery (new) ran down quickly and the headlights were dim. When we finally did get it (jump) started I put a voltmeter on the battery and got 12.8 volts. I then checked the voltage at the "Bat" terminal of the alternator, there I got 15+ volts. What am I missing here, it seems to me I should get the same reading. The alternator is putting out, but the battery is not getting it. The car won't be running till we get our "new" gas tank, but I want to head this potential problem off.


From Phil:

You have a big voltage drop or resistance somewhere, and while the cables are a natural place to check, I'd also check your ammeter gauge. They can still read, and yet, won't allow enough current through to charge the battery, when bad. A common problem with 60's Mopars, and a real bear to find, if you don't know about it. Also, anyplace that is dropping 3 or so volts, will probably be warm, check carefully with your hand at your connections, there may be some unseen corrosion at some point, that is causing resistance. Check the firewall connector too.

From Loren:

I see mention of electrical problems with a '64 Imperial and questions of where the power may be going, or, in my case, not able to go, and it brings to mind the last time my car rode home on a flat bed tow truck.

My electrical problem was caused by a loose connection between one of the wiring studs pressed through the metal plate that holds the ammeter magnet and needle and the metal plate itself. There are two studs extending from the back of the gauge. The positive circuit that powers the car passes through the brass plate, in on one stud and out on the other. The magnet on the bottom of the ammeter needle just reacts to the changing magnetic field created by the power passing through.

One of my splined posts had spun in the brass plate and was therefore not in direct contact at all times. The break in the circuit caused my car to die when coasting to a stop at a stop light. After wiggling wires, cleaning contacts and messing around for about an hour, it started again, once, and then never would start again. Hence the ride home on the flat bed tow truck.

When the short was located, I repaired it by replacing the pressed in studs at the back of the ammeter with hex head bolts, star washers and nuts that locked the bolts against the brass ammeter plate.

Before you spend a lot of money replacing major electrical components, check the ammeter gauge. If the studs move in relation to the brass plate this may also be the source of your problems. A clue to the problem would be deformation or melting plastic at the back or bottom of the ammeter gauge.

This problem is not a loose wire connection to the ammeter studs but a faulty connection between the stud splines and brass plate.

When I put my ammeter gauge back together, I found my headlights no longer get dim at idle like they have done since I first got the car.

Question from Loyal (1966):

I need to replace the positive battery cable on my '66 Crown Coupe. I have already replaced the negative cable which was incredibly easy, but the positive cable looks a bit more complex. I don't know where the positive cable runs to, furthermore the are (I believe) 2 smaller red wires running from the main cable. Where do they go? Is this a hour job? 15 min? do I need to have the car lifted? (I had heard that one cable may run back under towards transmission).


From John:

The positive cable runs to the starter. I doubt you will find a new one, but might get lucky with a decent used one. They are the same for a number of years. Another thing I've seen done is cutting the upper end of the cable off after the starter relay & installing a new top section. This is probably the easiest solution if originality is not all that important.

From Bob:

Year one has them but they are probly high priced.

Question from Demetrios (1968):

My battery got drained after many days of inactivity, and I traced this down to interior lights not turning off with doors shut (it did not take long since its obvious). THe light on the roof does shut off, but the lights on the doors don't. When I mannually push the little button that disconnects the ground with one door open and all others shut, the roof light goes off, and I notice a change in the brightness of the door light, but it does not go off. The same repeats for all 4 doors. Any thoughts on what needs help? I am wondering if this is related to the thumb wheel that controls the brightness of the dash. As most '67-'68 owners know, when this wheel is pushed all the way to one end, the interior lights turn on. I am certain the wheel is not in that position, but I am wondering if something is messed up with the wheel. If I can't find the problem, I will remove all 4 light bulbs. That would suck because I like these lights. For now, I disconnect the battery.


From John:

I would suspect there is a blown fuse. Many years ago I had a '63 & mounted an 8-track player directly below the fuses. I guess it was close enough that vibration would make contact & blow one of the fuses & I got the condition you describe.

It was the fuse that controlled the dome light. That light would go out & the map light would stay on very dim. I moved the tape player to a different location & never had further problems. I don't quite understand that when a fuse blows & one circuit goes out yet its now allowing some power someplace else that can't be turned off, short of disconnecting the battery.

From Dick:

Check the map light switch position - in the center of the dash. I think someone turned it on for you.

From Paul:

Does the roof light go on and off with the thumb wheel for the dash lights? If it does, there probably isn't anything wrong with the thumb wheel.

Does it have a map light switch? I know in my '65 (different car completely, I realize) the map light switch turns on the door lights along with the map light, in addition to them working with the interior lights through the door switches. If so that maybe another place to look.

Question from Jason (1968):

The original negative battery cable on my '68 ht has seen better days, and probably should get changed one of these days. The only issue is that I'm slightly hesitant to take it off because it's held on the engine side by one of the bolts that holds the intake down, and I don't want to inadvertently cause a vacuum leak by taking the bolt out and putting it back in. Am I just worrying too much or is there a slick way to do this?


From Steve:

Not to worry. Removing the one bolt from your intake won't cause any leaks. We've done it 100's of times at our shop with no problems.

From Demetrios:

You will not have a leak. The manifold and head were stuck together for 34-35 years now. Removing the bolt for a a few minutes will not unbond those parts for sure

Question from Mac (1968):

I have put both a new alternator and a solid state voltage regulator in my 68 Imp. For some reason it still is not charging like it should. If I am driving with the lights and heater on it is the meter shows a slight discharge. When i go to stop, and the lights and heater are on, the meter almost maxes out on discharge. But when driving during the day the meter shows a charge, but only to the first increment on the meter. Dick B. said to chek the meter and make sure it is centering properly. I did, with nothing on and at and idle the needle sets dead smack in the center. I am going to get the alternator tested again today. Maybe they sold me a bum alternator. Also, the previous owner put new ends on the battery cable instead of replacing them, could that be a problem as well.


From Dick:

Unless your idle is really slow, it should charge at idle. I suspect the voltage regulator, if the wiring is all clean and tight on the alternator and the regulator. By the way, verify that when everything is off in the car (like when you disconnect one battery cable) that the ammeter really returns to dead zero. If not, you need to adjust your thinking to realize the true zero point, maybe you are charging at idle, but the gauge is off a tad.

From Carmine:

This is a very common Mopar problem. Try disconnecting the wiring harness at what is known as the "bulkhead disconnect". This is the huge bundle of wires located to the left of the master cylinder. (All right/left terms are done as if sitting in the drivers seat). There should be about 3-4 separate harnesses. Disconnect these wires very slowly and carefully, the wires shouldn't be brittle, but likely the plastic removal tabs will. You will probably break them anyways, but it's not the end of the world. Now look at all the spade connectors in the male end of the harness. Most likely, they'll be a greenish shade. Go to a Radio-Shack/Electronics store and buy a can of electrical contact cleaner, and perhaps a few tiny cleaning brushes. Spray both the male & female ends of the bulkhead with the cleaner and use the brushes to clean all of the metal contacts. When you think it's clean enough (no green, just bright metal) go back and clean them again. The design problem is, all charging current is passed through this connection, on it's way to the amp gauge. After a few years, the connection starts to corrode, resistance builds, and then the battery will only charge at higher RPMs. 

> Also, the previous owner put new ends on the battery cable instead of replacing them, could that be a problem as well. 

Yes, it could be, for the same reasons listed above. It would be a good idea to clean every connection between the battery and the charging system, because after a while they'll all get old. I've noticed on my '89 5th Ave that the entire bulkhead is sheathed in rubber (minds out of the gutter please). The '89 5th Ave is a very old design, with roots back to 1976. As the demands on the electrical system grew, this system of moisture protection and a better attachment system were the solutions to an old design fault.

From Bill:

The battery should not make it discharge after it is started unless there is a short some where. Check the alternator for output. Also make sure your belts are tight enough. Normally the parts shops have diagnostic equipment to check the entire system. Ask them when you take the car in to check the alternator.

Question (1972):

I need a battery replacement for my '72 Imperial.  What brand should I be looking at?  I went shopping today and looked at AC Delco's line but couldn't find the right size.  What's the best battery out there?  

Reply from Chris:

I've had great success with Interstate batteries in my newer cars for 20 years, but for some reason I always put a Die Hard in my oldies. The one in my Imperial that I replaced in 1994 was probably ten years old, so another Die Hard went in there.  One problem: the Gold Series Die Hard does not come in a proper Group 27 size, which is the exact fit for your car. Only their low-line "WeatherHandler" does. Anything else will be slightly taller or narrower and won't mate well with your battery hold-down bracket. Have you considered an original style reproduction Mopar battery? You can find them in the classifieds of the Old Cars Weekly or even through your local Mopar dealer. Have them check the Mopar Performance catalog, as they are listed in there. They are drop-shipped dry and you take them to your local auto parts store to have the acid put in. Not the most modern and you have to check the water level like the old days, but they do work and they look correct.  A friend of mine swears by the high-output gel-cell Optima batteries, which run about $30 more but put out incredibly high CCA (cold cranking amps) and last a long time.  They also won't leak, even if they're stored on their side (why you'd do that, I don't know!).  By the way, my Imperial and its Die Hard sit idle for months at a time (I am driving it today for the second time since October) and needs to crank a long time to fire up, but it always does! (I do not use any sort of charger or tender, by the way, and I live in a warm climate that can be harder on a battery than a wintery land...)

Follow-up from Kurt:

The Optima is a spiral-cell AGM battery (looks like a six-pack) rather than a gelled electrolyte battery.  Gel-cells are good for things like UPS's and alarm systems but don't have the cycle life or power density of a wet cell battery.  They also have different charging and discharge voltages so if you put one in a vehicle without a special voltage regulator, you'll kill it in short order.

Question from Pete (1973):

Does anyone know why my 73's lights, radio, a/c, etc dim when I've applied the brakes. Then when I give her the gas we are bright again? We have a new alternator, battery, and voltage regulator.


From Norm:

Both Motor's and Chilton's car books claim this is a condition caused by High Resistance in the battery cable circuit. I personally have found this to be true only some of the time.

From Mike:

Sounds like idle adjustment or slipping alternator belt at idle. 

From Bruno:

Check for a good battery to engine and engine to chassis ground. This is usually overlooked when checking out electrical problems.

Follow-up from Dave:

I have heard this advise before.  Can anyone tell me where this is located?

Reply from Bob:

I think that the correct place is to use the back of the cylinder head. There should be an empty threaded hole there that corresponds to the alternator bracket hole on the front of the head, if not use the back intake manifold bolt to secure the grounding strap.

Question from Terry (1974):

Well, the continuing saga of replacing the timing chain on my 1974 440 has taken an interesting bend today. Again, getting up early to beat the heat, I finished replacing the alternator, A/C compressor (that is putting them back on the car after having removed them to put on the new timing chain). Then it was a matter of putting hoses, belts, vacuum tubes, etc etc. All is complete, and now it is time to drop in the freshly charged battery.... ZZZZZSSSSTTT!!! The small wire coming from the positive battery cable shorts in two!! Gee, this is new... The last time I had a battery in this car, it was fine electrical wise. Now a short.  I checked the alternator, checked other items. The Ohmmeter says the battery is grounded even with the ground battery cable off.  Any ideas on what I could have done to it?


From Czar:

Sounds like you simply have a wire crossed somewhere at the starter or alternator. Or you may have pinched a wire that is grounding out. None got caught under a valve cover did they? Or the timing cover or water pump? Just an idea. Sounds simple enough - not too many wires to re-check that has to do with what was removed to do the timing chain! Did you remove the distributor? Did you check for pinched or broken wires or parts in that since the chain slipped?

From Dick:

The wire that burned in two is probably a fusible link. The color will tell you what amperage it is, and NAPA will have a replacement for it. Don't replace it with a plain wire, it is the protection for a serious short, which you had, apparently. Even though you checked it, I am always suspicious when anything on the alternator has been disturbed. Since you can see the short with your ohmmeter, try disconnecting all the wires from the alternator to see if the short clears. If the problem is not there, most likely there is a wire pinched between metal parts somewhere, and it pretty much as to be on the alternator main lead, or perhaps the large wires that go to the ammeter in the dash, assuming you have same, or to the fuse block if you don't. 

Question from Forrest (1975):

I have a 1975 Imperial LeBaron coupe that I'm trying to get running. I have cleaned all connections from the battery and the starter will barely turn the engine over. I have checked the fuses and on fuse 3 and 4 there is a 8 to 10 amp fluctuation. Fuse 5 has a constant 25 amps.  Does anyone know what could be causing this problem?  The buzzer sounds weak and the dome light dimly pulses. The windows, locks and power antenna will not work but the dash gauges seem to work fine.  

Reply from Elijah:

Have you cleaned the connection where the negative battery cable is bolted to the engine? Also check the connections for the amps gauge in the dash -- all the current for the car accessories runs through that gauge, and the connections can loosen over time.

Follow-up from Forrest:

I put in a fresh smaller battery and used the battery charger to boost and got it to turn over and start.  I have found what is making that noise, it looks like a relay and it is on the passenger side with three wires coming in. Two of the wires have 15 amps and the third has 2 amps. Could this be my problem and just need replaced?  

Question from Carl (1981-1983):

I have my '81 EFI Imperial up and running well now.  I will share what I learned very soon.  I just met a guy named Gary who owns an 81 Imperial EFI that just (80 > miles ago) came out of a computerized tune up at a dealership in Anaheim,  CA.  He drove the car back to San Diego and it was running great.  Suddenly he has a problem which has stopped him cold.  He let  the car sit for awhile and it needed a jump. When he applies the cable it arcs back a him.  And ideas what this is all about?

Reply from Dick:

The arc is caused by the dead battery suddenly seeing a source of current from the donor car and is probably a symptom not a cause. (I hope he knew to turn off the motor on the donor car BEFORE jumping the 81, if not he took a real chance of burning out the alternator on the donor car). It is also a good idea to disconnect the white cable connector that powers the EFI while you are hooking up the battery cables to jump start. You have to reconnect it, of course before it will start! The real problem is that something is on in the 81, and it is draining the battery. The method for finding the culprit has been discussed here many times, but basically it involves disconnecting loads one at a time until the current drain (as monitored with a Multimeter) goes to zero. The last item disconnected is the culprit. Something's to check first are the glove box and all other interior lights, the seat controls, the power door locks, the hazard warning system, the power antenna, the sun-visor vanity lamps and garage door opener, the under-hood lamp, and anything else that is powered even with the key off. The EFI system also draws a small amount of current (assuming the car still has its original systems), but you are looking for something upwards of 0.1 AMP. The alternator is also a possible culprit. If you are not comfortable with trouble shooting electrical problems, you would be best advised to find an honest auto electrical shop to do it.

Question from Leo (1983):

Lately, my 83 has been quietly disconnecting the battery from the rest of the car. When I get in the interior lights all come on and then everything goes out and the amp gauge light glows very dim and eventually goes out. After waiting 10 to 30 seconds everything comes back on and away I go!. Apparently it has been happening during the night as several times the last month I noticed the clock has started over again at 12:00 am. I have checked the battery cable connections and they are very tight. Any ideas?


From Dick:

Maybe you have a cat that sleeps under the hood, and is disconnecting the battery to use for its portable heater?

No, well then I'd inspect the fusible links - if the clock is resetting, the whole shebang is going dead, so it is probably the main fusible link (I think that is the red one) that is intermittent. Funny that it doesn't let go when you are driving, though. Try wiggling that whole battery cable end of the harness with the lights (or some other item you will notice immediately) if it momentarily quits. The underhood light would be a good indicator too, if it works on your car.

From Rob:

I have just recently had the same problem with my '83. Loaned her out to Dad, when I got her back, the clock was wrong. The trip odometer, which I had reset about 10 gallons ago said 7.6 miles. My dad said the "odometer seemed to have gone backwards," but his eyes aren't so hot these days. It has since reset the clock a couple of times, only once in my presence, never while running.

From Allan:

I'm not positive about the wiring on that car but from what I remember all the power goes to the starter relay and then through one of the bulkhead connectors. Check the ground cable where it attaches to the frame/engine . I would take it off, clean it and re tighten it. Do the same with the positive, just don't connect it to the frame. Also , I know you said the battery terminals were tight but did you take them off and clean them? I've had experience that they looked good but had some kind of buildup on them, almost like they had plated themselves. If everything looked good at these points , check the bulkhead connector pins, on a number of Chrysler products that I have worked on the pins have corroded and on occasion the wire had corroded where it was crimped to the pin, causing an intermitting stalling, no power, or run problem that drove us crazy. Sometimes you can duplicate the problem by shaking the harness with someone carefully watching the lights while you shake them but it doesn't always work.

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